2000 Pontiac Bonneville Problem...Stumped
 

I guess I fouled up the whole site by posting my FIRST post in the wrong section...still I would like some advice on my predicament...2000 SSEi...picks up a wicked stumble only after the engine is hot...sometimes dies when you try to accelerate away from a stoplight...other times it has an erratic idle issue at lights...I am stumped and thought I could turn to this Forum for help

Re: 2000 Pontiac Bonneville Problem...Stumped
 

do you have a check engine light on? how many miles are on the car? what kind of maintenence have you done recently?

Car has 184,000...I drive it 6 days a week 100 miles a day..mostly at speed on the interstate...I had not done anything to it until it started acting up...it had plugs and wires about a year ago...since it started showing its butt it has got a mass airflow sensor...seemed to run fine after that for about a week...then a new catylitic converter...old one was very plugged....made no improvement at temp but made it run alot better cold...today I replaced the IAC motor...the service engine light is ON and has been for awhile now...I get several codes...TCC Code...trans has not gone into overdrive for two years supposedly related to a sun gear problem...misfire bank #1...fuel level problem...gauge is erratic...not alot engine related...car runs fine cold but after alot of in town driving it seems to start having issue...then if you drive it up to speed for awhile and come to a town and slow down or stop at a light the problem is gone...unless you do that repeatedly

disconnect the front O2 sensor, go for a ride, if the car run good, change your O2 sensor and reconnect.

I agree with Mike. That sounds like the most likely culprit at this point. It could have been what helped plug up your cat, too. When you replace it, replace only with an AC/Delco O2 sensor. Bosch and Borg/Warner do not seem to hold up in our cars.

Wow thats a different direction for me to go in...I will do that in a little while and see what happens...Thanks

you said "misfire bank 1" that is not an accurate description of a code.
You would either have a Lean or Rich Bank 1 O2 or you have a misfire in cyl number 1, either way im betting that this is your problem

I don't have my scanner here it is at work and I don't want to drive to Indy and get it...I have a Snap On unit...it was something like that

With that many miles, don't rule out a clogged catalytic converter. They're known to do that to performance when the grids swell from heat, cutting off exhaust flow.

if you read above, bill, you would see that he has already replaced it once